At Wakodahatchee Wetlands in Delray Beach, Florida, these two Double-crested Cormorant chicks beg incessantly for their parent to feed them. Adult males and female are indistinguishable, but I'll assume this is the mom.
Instinctively, they peck at her yellow gular pouch to stimulate her to regurgitate.
One chick thrusts its beak into her mouth.
It reaches into her throat...
...deeper and deeper!
Its head is disappearing!
The second chick takes its turn.
The outlines of the youngster's sharp upper and lower mandibles are visible halfway down the mother's throat.